Noah ended Jacob's 14-year reign as the top baby name for boys in 2013, while Sophia was the most popular name for girls for the third straight year, the Social Security Administration announced Friday.

Jacob slipped to third; Liam was second. Among girls, Emma and Olivia ranked second and third, respectively.

The list — released annually just before Mother's Day — is the most complete of the popular baby name lists because parents supply the information when they apply for their child's Social Security number. New parents in 2013 applied for a number for 4 million babies, the federal agency says. Other baby name lists are based on parents registering names with a particular site.

Noah as the most popular name for boys is the first new name at the top since 1960. Social Security says two boys names – Jacob and Michael – have alternately been No. 1 until now. Noah has been in the top 10 for years.

Bruce Lansky of Minneapolis author of almost a dozen books on baby names, suggests that Noah's supplanting Jacob at the top has to do with hard and soft sounding names.

"Parents are choosing softer names because the image of what they want in a son is a kinder, gentler, more considerate and more empathetic son. They're thinking soft and sensitive rather than hard and hyper-masculine," he says. "Not that Jacob is macho, but Jacob shortens to Jake, which is a macho name. Michael could be Mike."

Past research by Jonah Berger of the University of Pennsylvania has shown the effect of sounds on parents' baby name choices.

Lansky says biblical references are popular for boys because they "create the illusion of good values and good character," while parents are choosing names for girls that are "attractive, glamorous and even elegant," such as Sophia, Olivia, Isabella and Ava.

Jennifer Moss, founder of BabyNames.com, a Los Angeles-based website since 1996, says her site had Noah and Liam as the top boys names for the past three years, with Liam always at the top.

Now, she says the trend is changing.

"We already have Noah on the way down," Moss says. "Because of the Internet, I think names are trending faster than 20 or 40 years ago. There was a time when Mary was the No. 1 name for like 40 years. Now, by the time it's hit the top of the popularity charts, it's not popular anymore."

Social Security started compiling and releasing its baby name list in 1997, but the agency has data on baby names for each year since 1880. Those lists are available on its website, www.socialsecurity.gov